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You'd be forgiven for thinking this incredible picture is an artist's impression of a planet forming around a star.

But it is in fact the most detailed real image of a planet's birth ever taken, revealing a phenomenon astronomers could only theorise about a few decades ago - and one that could help explain how the solar system formed.

The planet-forming disc surrounds HL Tau, a sun-like star around 450 light-years from Earth in the constellation Taurus.

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Pictured is the best image ever of planet formation revealing multiple rings and gaps that herald the presence of emerging planets as they sweep their orbits clear of dust and gas

The image was taken as part of the testing and verification process for the Atacama Large Millimeter/submillimeter Array's (Alma) new high-resolution capabilities.

Alma, located in Chile, uncovered never-before-seen features in this system, including multiple concentric rings separated by clearly defined gaps.

'These features are almost certainly the result of young planet-like bodies that are being formed in the disk,' said Alma Deputy Director Stuart Corder.

'This is surprising since HL Tau is no more than a million years old and such young stars are not expected to have large planetary bodies capable of producing the structures we see in this image.'

An artist's impression of a planet-forming disc. Newly formed planets can be seen traveling around the central host star, sweeping their orbits clear of dust and gas. These same ring-link structures were observed recently by ALMA around the young star HL Tau

All stars are believed to form within clouds of gas and dust that collapse under gravity.

Over time, the surrounding dust particles stick together, growing into sand, pebbles, and larger-size rocks, which eventually settle into a thin protoplanetary disk where asteroids, comets, and planets form.

Once these planetary bodies have enough mass, they dramatically reshape the structure of their natal disk.

THE SECRET TO THE SUCCESS OF ALMA - HEIGHT AND DISTANCE

Alma's highest receivers sit on a plateau some 16,500ft (5,000 metres) above sea level.

The secret to Alma's incredible resolution comes from two factors: height and distance.

The observatory's highest receivers sit on a plateau some 16,500ft (5,000 metres) above sea level.

This is far above most of Earth's atmosphere and water vapour, which obscures observations. Astronomers working in Alma's facility at 9,500 feet (2,900 meters) must use supplemental oxygen for extended stays.

The system currently comprises about 50 functional antennas. When the array is finished, there will be 66 of these receivers that can be moved as far as 16km (9.9m) apart.

The antennae capture astronomical signals from the sky individually, then combine their results in a supercomputer to get precise information about where the signals come from.

Researchers say it is similar to how we use our two ears to locate sounds around us, but on a universe-size scale.

This high-resolution not only lets Alma observe young planetary systems, but also pin down hydrogen and life-building blocks in gas clouds. The array can also track the evolution of galaxies. 

They fashion rings and gaps as the planets sweep their orbits clear of debris and shepherd dust and gas into tighter and more confined zones.

The new Alma image reveals these striking features in exquisite detail, providing the clearest picture to date of planet formation.

Its new high-resolution capabilities were achieved by spacing the antennas up to 9.3 miles (15km) apart.

HL Tau's surroundings, as seen by Hubble. HL Tau is a sun-like star around 450 light-years from Earth 

Final antenna is added to Alma array to help explore the cosmos

Images with this level of detail were previously only seen in computer models and artist concepts.

'This new and unexpected result provides an incredible view of the process of planet formation,' said Tony Beasley, director of the National Radio Astronomy Observatory (NRAO).

HL Tau is hidden in visible light behind a massive envelope of dust and gas. Since Alma observes at much longer wavelengths, it is able to peer through the intervening dust to study the processes right at the core of this cloud.

This is an artist's impression of a young star surrounded by a protoplanetary disc in which planets are forming

'This is truly one of the most remarkable images ever seen at these wavelengths,' said NRAO astronomer Crystal Brogan.

'The level of detail is so exquisite that it's even more impressive than many optical images.

'The fact that we can see planets being born will help us understand not only how planets form around other stars but also the origin of our own solar system.'